Supporting Plate Incorporating An Adjustable Asymmetry Function For Shaped Skis

ABSTRACT

The invention relates to a supporting plate incorporating an adjustable asymmetry function enables the carving turns to be performed in such a way, that the skis run along two parallel curves, which in ideal circumstances match closely the arcs of two concentric circles, that no additional energy is needed to maintain the skis in parallel position throughout the turn, and that the turns are executed without unwanted vibrations and with normal, not much increased physical activity. The asymmetry of the skis, that is the assignment of a left and a right ski, is set up in a control assembly, comprising a weighting member, made of two balls, one steel ball and one highly compressible ball made of rubber or similar material, and two mechanical stops, as well as a housing, where an aluminum piston with a magnet acts as a find regulating device. The left and the right ski are set up by the disposition of the balls and the outside ski in a turn, respectively, are distinguished. The supporting plate of the inside ski allows a maximal flexion of its ski, while the supporting plate of the outside ski restricts successively the bending line of the ski and thereby slightly increases the radius of its turning arc. Consequently, the tracks of a turn are two parallel curves matching closely the sections of two concentric circles, spaced at a distance between the skis.

FIELD OF THE INVENTION

The present invention relates to the alpine skiing equipment, in particular to safety-binding assemblies for shaped skis and to the means for improving the performance of such skis.

BACKGROUND OF THE INVENTION

The invention is based on the objective of providing a supporting plate, positioned between the ski and the ski-binding, such as to enable the skier to execute a carving turn in such a way, that in ideal circumstances the skis would track two parallel lines matching closely the arcs of concentric circles, and that no extra energy would be needed to sustain a parallel position of the skis throughout the turn. In addition, the solution of the technical problem should allow the skier to make an ideal carving turn with no excessive vibrations and without requiring the skier to increase his/her physical efforts much above normal activity. Besides, the solution of the technical problem should be undemanding as far as technology is concerned, and also economically feasible.

For decades the skiing technique has been based on performing the turns by using in effect only one ski that is the outside ski. The trace of such a turn is a single line. By contrast, with carving skiing technique, which is practiced by shaped skis, also referred to as super sidecut skis, the weight Is basically equal on both skis and the edge angles of the skis are equal. Consequently, the skis draw a trace in a form of two parallel arcs spaced apart at a distance equal to the gap between the skier's feet, which is about 0.5 m when the turning is intense and executed at high speeds. A correct carved turn can be carried out only, if the construction and the deformation of the system configured of the ski and the supporting plate are such as to allow the ski edge to be curved into an ideal contour congruent as much as possible to a portion of a circle. With the edges bent in such a way the skier literally carves Into the snow and the trace of such ideal turn is a pair of parallel curves nearly matching the arcs of two concentric circles.

Due to physical limitations and due to problems originating from these limitations, it is hard to carry out an ideal carving turn. For illustration, an example of a typical intense carving turn is presented in FIG. 5, having a radius of 5 meters and the distance between the inside and the outside ski of 0.5 meters. The weight on both skis is equal, as each ski carries a half of the skier's weight F_(g), and both skis have equal edge angle α relative to the surface of the snow. If the inside and the outside ski are considered as two separate systems, it is evident from FIG. 5, that the skier makes a similar arc with the inside and the outside ski, respectively, and that both circles, which are spaced at a distance between the skis (0.5 m), have equal radius. However, near the middle of a turn, the circles intersect, because the skis are not running along parallel round arcs through the entire turn. At the beginning of a turn the skis are parallel, while toward the midpoint their tips tend to close like a snowplow. As a result, soon after the beginning of a turn the skier has to put in much effort to hold the skis in parallel position.

Due to ergonomic characteristics of the human body, and especially when the turns are performed on difficult terrain and with higher speeds as well as in critical situations, the weight exerted on the outside ski is increased as compared to the weight exerted on the inside ski. Consequently, the weight on the inside ski is lower, and besides, the tilt of the outside ski edge becomes higher than the tilt of the inside ski. From FIG. 6 it is evident, that the resultant of the forces exerted on the outside ski is greater, therefore the outside ski bends more than the inside ski. Due to greater bending of the outside ski and due to its higher tilt relative to the snow surface, a curve carved by the edge of the outside ski matches a circle with a smaller radius than the desired turn, moreover, smaller radius than the circle arc carved by the inside, less weighted and less tilted ski. As a result, the skier should put in more of his/her energy to sustain the skis in parallel position and should continuously make corrections in the turn, while the courses of the skis deviate more and more from circle arcs. Hence, the sensitive dynamic balance of the skier is destroyed, one ski lags behind the other and the upper part of the skier's body is rotating. All these effects together prevent the skier to carry out the turns as intended, causing a loss in speed and balance and an increase in energy consumption, so the skier could be exhausted quickly.

FIG. 7 shows an example of an ideal carving turn where the skis trace two parallel lines throughout the course of the turn, the skier is in a dynamic balance at all times and no unnecessary consumption of inner energy is required to sustain the skis in parallel position. The above turning characteristics enable the skier to execute a turn in a fastest way, which is extremely important for the alpine skiing racers. With the skiing equipment known so far such perfect turns could be performed only by an excellent skier, who could weight the inside ski slightly more than the outside ski and who could at the same time increase the tilt of the inside ski by several degrees in comparison to the tilt of the outside ski. With regard to ergonomic aspects, such performance of a turn would be extremely hard to manage and moreover, it would not be feasible for a majority of skiers, as it would result in high dynamic instability.

The supporting plate incorporating an adjustable asymmetry function enables the skiers of various grades of skill, ranging from recreational skiers to ski racers, to perform perfect turns by taking advantage of the adjustment possibility offered by the solution according to the present invention.

PRIOR ART

Known supporting plates such as for example the World Cup-Air plate manufactured by Vist, are designed, firstly, to offer the basic function of a lifter beneath the ski-binding preventing the boot to touch the snow when the skier makes a turn and thereby allowing the skier to sustain the natural flexion of the ski, and secondly, to absorb vibrations.

In the U.S. Pat. No. 6,659,493 a connector plate for ski bindings of snow skis or snowboards is described which enables better execution of turns, improves the flexibility of skis or snowboard and ensures better absorption of vibrations. The connector plate is universal, which means that it can be applied with any type of skis or snowboards and with any type of ski bindings, however its advantages are most prominent with the shaped skis. Two connecting segments, constructed from an elastic layer made of rubber or silicon, realize the above characteristics. Along the lateral axis of the elastic layer, which lies perpendicular to the longitudinal axis of the ski or snowboard, at least one solid supporting element is located, dividing the elastic layer into two regions: one region is compressed and the other expands during the flexing of the ski or snowboard. In addition, the construction allows for longitudinal movement in the elastic layer of the connecting segments.

The support plate described in DE 198 43 866 A1 ensures an optimal line of a turn executed with shaped skis by lifting the boot to a higher position and thereby lessening the possibility for the boot to touch the snow at extreme carving angles, which would result in loss of edge grip. Besides, the plate is fixed to the ski by means of two bearing assemblies which allow certain sliding along the longitudinal direction and a predetermined torsion play relative to the cross axis of the support plate.

The device for improving the efficiency and controllability of skis disclosed in U.S. Pat. No. 5,758,894 has two elongated shaped plate-like elements, each having one end provided with locking members for fixing to the ski and another end provided with retention members, which allow the other end to slide longitudinally with respect to the ski. A toe unit or heel unit of a ski binding is fixed proximate to one of the ends. The same relative (center-of-gravity) position is thus maintained at all times between the boot and the ski, and thus the possibility to control said ski is always optimal.

Beside the basic function of lifting the skier and shifting the boot from the snow in the turns, the known supporting plates ensure various additional functions, for example absorbing of vibrations, enhancing the flexibility and improving the controllability of skis. In contrast to known constructions of supporting plates or devices, with the supporting plate according to the present invention a challenge of ideal carving turning is tackled with the aim to enable the skier to execute a perfect turn without superfluous consumption of energy and without excessive corrections. This aim is achieved by an asymmetry set-up assembly that prevents the skis to close into a wedge position toward the middle of the turn and ensures a parallel course of both skis throughout a turn. In addition, any unwanted vibrations of the front and the rear portion of the ski are absorbed by an adjustable feedback loop formed in the plate.

The behaviour of the skis in a turn can be compared with the behaviour of a motorcycle or a motorcar in a curve. A turn with only one ski touching the ground is comparable to a turning of a motorcycle, whereas a carving turn, which is performed with both skis on the ground, can be compared with a turning of a motorcar. As far as physical aspects are concerned, turning of a motorcycle is simple. In contrast, a turn of a motorcar involves turning of a pair of spaced front steering wheels and can be performed properly only by applying the Ackermann automotive steering principle, whereby the wheels are suspended separately so that the inside wheel can turn a bit tighter circle than the outside wheel. To achieve this, the inside wheel needs to be turned for a higher angle as compared to the outside wheel. The concept of a separate and different movement of the inside and the outside wheel represented an inspiration for the solution of a similar problem encountered when making a turn with shaped skis.

DESCRIPTION OF THE INVENTION

The supporting plate incorporating an adjustable asymmetry function has a special construction and Is fixed firmly onto the ski only in one transversal line in the front portion beneath the beginning of the toe piece of the binding, while in further three transversal lines, the plate is fastened flexibly in order to sustain maximum flexibility of the ski. The asymmetry set-up assembly, whose function is to discriminate the inside and the outside ski in the turn, whereby a distinct behaviour is assigned to the inside and the outside ski, respectively, is realized in the control assembly of the supporting plate by means of a weighting member, formed of two balls, that is one solid ball made of steel and one soft ball made of rubber or similar material. The weighting member may consist of a single steel ball. The construction of the supporting plate according to invention ensures also efficient suppression of unwanted vibrations.

The objects, features and advantages of the supporting plate according to the present invention are described in detail by reference to the accompanying figures showing:

FIG. 1 a longitudinal section of the supporting plate, fixed on the ski

FIG. 2 a top plan view of the supporting plate, fixed on the ski

FIG. 3 a top plan view of the supporting plate with a cover plate

FIG. 4 a a top plan view of the control assembly comprising two balls, the control assembly being shown in four operating positions, representing the right and the left turn, respectively, as well as the left and the right ski

FIG. 4 b a top plan view of the control assembly comprising a single ball, the control assembly being shown in four operating positions, representing the right and the left turn, respectively, as well as the left and the right ski

FIG. 5 a drawing of example 1 of the execution of a turn

FIG. 6 a drawing of example 2 of the execution of a turn

FIG. 7 a drawing of the execution of a turn by use of the supporting plate according to the invention

The object of the present invention is to construct a supporting plate for a ski binding of a longitudinally symmetrical shaped ski. The supporting plate according to the invention is fitted onto the ski in four transversal lines, I, II, III in IV, in eight points. The fitting is firm only in line I at the beginning of the toe portion of the supporting plate, while in other three lines, II, III, and IV, located toward the end of the supporting plate, the fitting is resilient in order to allow some sliding of the plate in the longitudinal direction. Such fastening of the plate enables a maximal natural bending of a weighted ski, as the plate moves with minimal friction in longitudinal direction along the ski depending on the weight and consequently on the bending of the ski.

The supporting plate comprises a stretching mechanism 4 for spring 16, a spring 16, a control assembly 5, a rear lever 12, a pullback arm 10, and a rear arm 11. The control assembly 5 includes a weighting member, made of two balls 17 and 18, two mechanical stops 25 and 26, and a housing with a fine regulating device in a form of an aluminum piston 6 with a magnet 19. The said constituent parts build an elaborate mechanical system, designed to enable the skier to perform ideal carving turns by tracking two parallel curves, which match the portions of two concentric circles, the said circular curves being spaced at a distance between the skis. The making of a turn is an intricate physical action, influenced by a series of variables, such as terrain characteristics, type of snow and speed of skiing as well as skill and psychophysical condition of the skier.

The supporting plate incorporating an adjustable asymmetry function consists of a toe portion 1, a heel portion 24, and a control assembly 5. To ensure a watertight construction of the control assembly 5, the washers are fitted on the side stops 25 and 26, and the aluminum piston 6 with a magnet 19 enters the interior of the control assembly 5 through gaskets, whereas the top of the control assembly 5 is closed tightly with a thin layer of hardened glass or similar material. The said parts of the supporting plate are preferably made of plastics, aluminum, various alloys or composite materials. The toe portion 1, the heel portion 24, and the control assembly 5 are covered by a few millimeters thick cover plate 3, which may be made of aluminum, various alloys or composite materials. Light yet robust materials should be chosen for fabrication of the supporting plate. As shown in the technical drawing in FIG. 2, the supporting plate is fitted to the ski 2 in four transversal lines. In line I, the plate is fitted firmly by a screw connection. In line II in the toe portion 1 of the plate, an oval hole is provided allowing a slight longitudinal movement of the plate by means of two simple distance pieces. In lines III and IV, the heel portion 24 of the supporting plate is fitted to the ski by means of larger distance pieces and specially shaped grooves 20, made in the heel portion 24. The method of fitting of the supporting plate described above allows a longitudinal motion of the plate, whereas the plate cannot be shifted sideways or in vertical direction. Owing to special fitting of the supporting plate and with the help of two transversal slits 9 made on the toe portion 1 and the heel portion 24, the supporting plate moves freely when the ski bends, and also adapts to the bent upper surface of the ski, the maximal shift of the heel portion 24 being larger than 5 mm at maximal bending of the ski. To lessen the friction, a thin pad 27 made of 0.4 mm thick rust-resistant sheet metal is placed beneath the heel portion 24 of the plate.

In the middle of the toe portion 1 there is a longitudinal groove along which moves the lever arm 14 of the stretching mechanism 4. The stretching mechanism 4 for the spring 16 consists of a housing, which is fastened with screws to the front section of the ski in a chosen position, and of a transversally fastened support 15 for the lever arm 14, the said support 15 allowing the skier to change the length of the arm 14 to control the tension of the spring 16. The spring 16 presses resiliently on the control assembly 5, which has a transversal groove along which travel the steel ball 18 and the soft ball 17 driven by gravitation force when the skis incline sideways. The operation of the control assembly 5 is evident from the FIG. 4 a, where the essential feature of the invention is presented, which is in that by a corresponding disposition of the balls 17 and 18 and by a suitable adjustment of the side stops 25 and 26 a symmetrically shaped ski is set up to be either the left ski or the right ski, whereas by the movement of balls, stipulated by the gravitation, the inside and the outside ski, respectively, in a turn are distinguished.

In the inside ski in a turn, a link is established between the stretching mechanism 4 and the lever 12 through a sequence of the following parts: the support 15 for the lever arm 14, the lever arm 14, the spring 16, the control assembly 5, the soft rubber ball 17, the fine regulating device, which is an aluminum piston 6, and the pullback arm 10. While the ski bends, the supporting plate moves longitudinally along the ski and pushes the lever 12, built-in in the lever housing 13, by means of the rear arm 11. The lever 12 is thereby triggered into action and it reverses the direction of the movement, since the pullback arm 10 is moving in the opposite direction than the supporting plate, and, depending on the lever arms, increases the amplitude of the movement of the heel portion 24 of the supporting plate. When bending of the ski is extreme, the heel portion 24 of the supporting plate shifts also for more than 5 mm toward the rear section of the ski, which means that at a 1:3 ratio of the lever arms the pullback arm 10 shifts toward the front section of the ski for more than 15 mm. Situated at the beginning of the pullback arm 10 is a fine regulating device, consisting of an aluminum piston 6 with a magnet 19 that enters through a gasket into the housing of the control assembly 5, where it pushes the weighting members with greater or lesser force, depending on the amplitude of the shifting of the feedback loop. As the soft ball 17 made of rubber or similar material is highly compressible, the bending of the ski is practically unimpeded and is consequently maximal, when the feedback loop is established over the ball 17.

In the outside ski in a turn, the link between the outermost elements, that is between the stretching mechanism 4 and the lever 12, is established over the steel ball 18 that is pushed against the housing of the control assembly 5 by the lever 12 over the pullback arm 10 with the fine regulating device, i.e. with the aluminum piston 6 and magnet 19. The control assembly 5 is fastened in the guides 23 located on the cover plate 3 by means of distance pieces. Such fastening allows longitudinal movement of the control assembly 5 only in the direction toward the main working spring 16. Thus, greater flexion of the ski instigates greater pressure of the front side of the control assembly 5 on the working spring 16. The strength of the working spring 16 can be adjusted by means of the support 15 of the lever arm 14. The magnet 19 ensures that the steel ball is centered exactly in the middle of the piston 6.

In the initial step of a turn, right after the skier tilts the skis, the supporting plates “identify” the inside and the outside ski, respectively. The supporting plate of the inside ski allows a maximal flexion of its ski, while the supporting plate of the outside ski restricts successively the bending line of the ski and thereby slightly increases the radius of its turning arc. The tracks of a turn, made in this way, are two parallel curves, matching closely the sections of two concentric circles, spaced at a distance between the skis.

The operation described in the above paragraph is presented in FIG. 4 a. It is suitable for longer turns executed with a greater radius and at higher speeds and is consequently appropriate for giant slalom and high speed disciplines. For good absorption of vibrations, it is very important that in each turn both the inside and the outside ski have a closed feedback loop over the steel ball and the soft ball, respectively, as the closed loop ensures that the unwanted vibrations of the front section and the rear section of the ski die out as quickly as possible.

FIG. 4 b presents the operation of the control assembly 5 comprising only one steel ball, which is limited on one side by a short stop, 25 and 26 and on the other side by a long stop 30. Such configuration is suitable for execution of extreme turns and for slalom races, where the turns should have a smallest possible radius and the edge angle relative to the surface of the snow should be high, and where greater difference is required between bending of the inside and the outside ski. In the outside ski, the absorption of vibrations is ensured by the feedback loop established over the steel ball, while the inside ski is left without the feedback loop as the aluminum piston 6 moves freely in the control assembly 5 passing by the steel ball. The absorption of vibrations is in this case provided by the stretching mechanism 4 of the spring 16 and by the spring 16, which acts as a shock absorber for the front section of the ski, while in the rear section of the ski, the elastic connection between the rear lever 12 and the pullback arm 10 as well as the spring 8 of the pullback arm 10 is used as a shock absorber. The pullback arm 10 travels through the spiral pressure spring 8 mounted in the longitudinal groove in the heel portion 24 of the supporting plate. At its front end, the spring 8 is restricted by a vertically movable stop 7, while at its rear end a spring blockade 21 is situated, which is used to set the initial elasticity of the spring 8, while during the run at every flexion of the ski the spring 8 is pressed additionally through a shift of the pullback arm 10 and its blockade 21. The energy preserved in the spring 8 in this way helps in straightening the ski as fast as possible at the end of the turn, where the flexion of the ski decreases. A similar role is assigned to the main working spring 16, which is positioned in the longitudinal groove in the toe portion 1 of the supporting plate. When the ski is not weighted and consequently is not bent, the working spring 16 elastically presses onto the control assembly 5, which is therefore in its outermost position as allowed by the manner of fastening through the guides 23. When the ski bends, the distance between the stretching mechanism 4 of the spring 6 and the control assembly 5 is decreased and the spring 16 contracts. At the end of a turn, the preserved energy ensures the quickest possible returning of the ski into straight position.

By choosing a suitable type of the spring 16 and by an adjustable regulation of the stretching of the spring, a desired behaviour diagram of the spring, i. e. the desired dependence of the contraction of the spring from the push force, can be achieved. By the aluminum piston 6, acting as a fine regulating device, the user can determine precisely, at what flexion of the ski the feedback loop over the steel ball will be established and how the behaviour of the ski will be changed as well as when, how, and how much the possibility of a free flexion of the ski will be decreased to allow the outside ski to draw a somewhat larger circle than the inside ski, whereby the said circles are concentric, spaced at a distance between the skis.

The supporting plate according to the present invention enables the skier to make ideal turns, provided that by taking into consideration both the relevant given factors as well as the desired skiing attributes, the skier sets up the following adjustable parameters on the supporting plates of the skis:

-   -   The strength of the main working spring 16 in the toe part of         the supporting plate: the strength is adjusted on the support 15         of the lever arm 14 by means of stretching mechanism 4.     -   Point of impact of the feedback loop and the weighting member:         is adjusted in the window 28 of the supporting plate by turning         fine regulating device, i.e. the aluminum piston 6.     -   The ratio of the lever arms of the lever 12: this ratio can be         set by means of a continuous adjustment of the length of the         upper arm of the lever 12 in order to define the ratio between         the lower and the upper lever arm, which represents the         amplifying factor. The movement of the rear arm 11 toward the         rear section of the ski is reversed by the lever 12 into the         opposite direction and is increased by the lever arms ratio. In         practice, the ratio of the lower and upper arm of 1:3 means,         that at great flexion of the ski, which causes the rear arm 11         to shift for 5 mm, the direction of movement of the rear arm 11         is changed by the lever 12 and the shift is increased by 3, so         that the shift of the return arm toward the front section of the         ski is greater than 15 mm.

Which of the symmetrically shaped skis will be the left ski and which will be the right ski, is determined by the disposition of the two balls and the mechanical side stops? In case only one ball is applied, the left and the right ski, respectively, are set up by means of suitable arrangement of a long side stop and a short side stop. 

1. A supporting plate incorporating an adjustable asymmetry function, comprising a toe portion 1, a heel portion 24, and a control assembly 5, wherein the setting up of asymmetry, that is the designation of the left and the right ski, respectively, is performed in the control assembly (5), consisting of a weighting member made of two balls (17, 18), two mechanical stops (25, 26), and a housing with a fine regulating device in a form of an aluminum piston (6) with a magnet (19); that the said weighting member, comprising one steel ball (18) and one soft, highly compressible ball (17) made of rubber or similar material, is adjusted by corresponding disposition of the said two balls (17, 18) and by adjustment of mechanical side stops (25,26); that the movement of said balls (17, 18) of the weighting member, stipulated by the gravitation, defines, which ski is the inside ski and which is the outside ski in a turn, and that the supporting plate of the inside ski allows a maximal flexion of its ski, while the supporting plate of the outside ski restricts successively the bending line of the ski and thereby slightly increases the radius of its turning arc, so that the tracks of a turn are two parallel curves, matching closely the sections of two concentric circles, spaced at a distance between the skis.
 2. A supporting plate according to claim 1, wherein the interior of the control assembly (5) is watertight and that the watertight construction is ensured by washers fitted on the side stops (25, 26), by a gasket at the entrance for the aluminum piston (6) with its magnet (19) into the interior of the control assembly (5) and by a thin layer of hardened glass or similar material at the top of the control assembly (5).
 3. A supporting plate according to claim 1, wherein the supporting plate is fitted to the ski in four transversal lines (I, II, III, IV) in such manner, that the fitting is firm, that is made by a screw connection, only in the first line (I) at the beginning of the toe portion (1) of the supporting plate; that in the second line (II), an oval hole is provided allowing a slight longitudinal movement of the plate by means of two simple distance pieces, while in the last two lines (III, IV) the heel portion (24) of the supporting plate is fitted to the ski (2) by means of larger distance pieces and specially shaped grooves (20) made in the heel portion (24), so that in the last three lines (II, III, IV) the fitting of the supporting plate is elastic in longitudinal direction and allows maximal bending of a weighted ski while the supporting plate travels longitudinally along the ski depending on the weight force and consequently on the bending of the ski; that when the ski bends, the supporting plate moves freely and adapts to the bent upper surface of the ski also with the help of two transversal slits (9) made on the toe portion (1) and the heel portion (24), the maximal shift of the heel portion (24) being larger than 5 mm at maximal bending of the ski; that in order to lessen the friction, a thin pad (27) made of 0.4 mm thick rust-resistant sheet metal is placed beneath the heel portion (24) of the supporting plate.
 4. A supporting plate according to claim 1, wherein in the middle of the toe portion (1) there is a longitudinal groove along which moves the lever arm (14) of the stretching mechanism (4) for the spring (16); that the stretching mechanism (4) for the spring (16) consists of a housing, which is fastened with screws to the front section of the ski, and of a transversally fastened support (15) for the lever arm (14), the said support (15) allowing the skier to change the length of the arm (14) to control the tension of the spring (16); that the spring (16) presses resiliently on the control assembly (5), which has a transversal groove along which travel the steel ball (18) and the soft ball (17) driven by gravitation force when the skis incline sideways.
 5. A supporting plate according to claim 1, wherein in the inside ski in a turn, a link is established between the stretching mechanism (4) and the lever (12) through a sequence of parts, consisting of the support (15) for the lever arm (14), the lever arm (14), the spring (16), the control assembly (5), the soft rubber ball (17), the aluminum piston (6) acting as a fine regulating device, and the pullback arm (10); that while the ski bends, the supporting plate moves longitudinally along the ski and pushes the lever (12), built-in in the lever housing (13), by means of the rear arm (11), whereby the lever (12) 18 triggered into action, wherein it reverses the direction of the movement, since the pullback arm (10) is moving in the opposite direction than the supporting plate, and, depending on the lever arms, increases the amplitude of the movement of the heel portion (24) of the supporting plate; that when bending of the ski is extreme, the heel portion (24) of the supporting plate shifts also for more than 5 mm toward the rear section of the ski, which means that at a 1:3 ratio of the lever arms the pullback arm (10) shifts toward the front section of the ski for more than 15 mm; that an aluminum piston (6) with a magnet (19), acting as a fine regulating device, is situated at the beginning of the pullback arm (10), wherein the piston (6) enters through a gasket into the housing of the control assembly (5), to push the balls (17, 18) with greater or lesser force, depending on the shifting amplitude of the feedback loop; that as the soft ball (17) is highly compressible, the bending of the ski is practically unimpeded and is consequently maximal, when the feedback loop is established over the ball (17).
 6. A supporting plate according to claim 1, wherein in the outside ski in a turn, the link between the outermost elements, that is between the stretching mechanism (4) and the lever (12), is established over the steel ball (18), wherein the steel ball (18) is pushed by the lever (12) over the pullback arm (10) and over the aluminum piston (6) with magnet (19), acting as a fine regulating device, against the housing of the control assembly (5) fastened in the guides (23) on the cover plate (3) by means of distance pieces; that such fastening of the control assembly (5) allows longitudinal movement of the control assembly (5) only in the direction toward the main working spring (16); that greater flexion of the ski instigates greater pressure of the front side of the control assembly (5) on the working spring (16), wherein the strength of the working spring (16) can be adjusted by means of the support (15) of the lever arm (14); that the magnet (19) ensures that the steel ball (18) is centered exactly in the middle of the piston (6).
 7. A supporting plate according to claim 1, wherein by choosing a suitable type of the main operating spring (16) and by an adjustable regulation of the stretching of the spring (16) by means of the stretching mechanism (4), a desired dependence diagram of the contraction of the spring from the push force can be achieved, while by the aluminum piston 6, acting as a fine regulating device, the user can determine precisely, at what flexion of the ski the feedback loop over the steel ball (18) will be established as well as when, how, and how much the possibility of a free flexion of the ski will be decreased to allow the outside ski to draw a somewhat larger circle than the inside ski, whereby the said circles are concentric, spaced at a distance between the skis.
 8. A supporting plate according to claim 1, wherein in each turn both the inside ski and the outside ski have a feedback loop closed through the relevant ball, that is through the steel ball (18) in the outside ski and through the soft ball (17) in the inside ski, to ensure that the unwanted vibrations of the front section and the rear section of the ski die out as quickly as possible.
 9. A supporting plate according to claim 1, wherein the toe portion (1), a heel portion (24), and a control assembly (5) are preferably made of plastics, aluminum, various alloys or composite materials, and that they are covered by a few millimeters thick cover plate (3) made of aluminum, various alloys or composite materials.
 10. A supporting plate according to claim 1, wherein in an alternative configuration of the supporting plate, suitable for execution of extreme turns and for slalom races, where the turns should have a smallest possible radius and the edge angle of the ski relative to the surface of the snow should be high, and where greater difference is required between bending of the inside and outside ski, the control assembly (5) has only a steel ball (18), which is limited on one side by a short stop (25,26) and on the other side by a long stop (30).
 11. A supporting plate according to claim 10, wherein in the outside ski, the absorption of vibrations is ensured by the feedback loop established over the steel ball (18), while in the inside ski which is left without the feedback loop, as the aluminum piston (6) moves freely in the control assembly (5) and passes by the steel ball (18), the absorption of vibrations is provided by the stretching mechanism (4) of the spring (16) and by the spring (16), which acts as a shock absorber for the front section of the ski, while in the rear section of the ski the elastic connection between the rear lever (12) and the pullback arm (10) as well as the spring (8) of the pullback arm (10) is used as a shock absorber; that the pullback arm (10) travels through the spring (8) mounted in the longitudinal groove in the heel portion (24) of the supporting plate; that at its front end, the spring (8) is restricted by a vertically movable stop (7), while at its rear end, a spring blockade (21) is situated, which is used to set the initial elasticity of the mounted on the pullback arm (10), wherein the energy preserved in the spring (8) in this way, helps in straightening the ski as fast as possible at the end of the turn, where the flexion of the ski decreases; that faster straightening of the skis is provided in addition by the main operating spring (16), positioned in the longitudinal groove in the toe portion (1) of the supporting plate, wherein the spring (16) elastically presses onto the control assembly (5), when the ski is not weighted and consequently is not bent, so that the control assembly (5) is in its outermost position as allowed by the manner of fastening through the guides (23), whereas when the ski bends, the distance between the stretching mechanism (4) of the spring (6) and the control assembly (5) 18 decreased and the spring (16) contracts, while the preserved energy ensures the quickest possible returning of the ski into straight position at the end of a turn. 